While the drug background in forensic laboratories has been quantified, the processes that most contribute to the background have not been extensively researched. This work presents both qualitative visualization and quantitative analysis of the spread of simulant drug particulate during the process of taking net weights. The process was modeled using three masses of powder (0.2 g, 2 g, and 100 g). The net weight process, in which the mixture was poured onto weighing paper, was mimicked and the resulting aerosolized particulate was allowed to settle. Wetted cotton swabs were then used to sample 6.45 cm2 (1 in2) squares extending up to 61 cm (24 in) away from the weigh paper. The swabs were then extracted and quantified using LC-MS/MS and two-dimensional color plots were created to visualize the magnitude of particulate spread. Qualitative flow visualization of the process, accomplished using laser light sheet videography, was also completed to support the quantitative extraction experiments and provide a visual representation of the mechanism of particulate spread. Surface concentrations were found to be highest in the area immediately surrounding the weigh paper, though transport as far as 61 cm (24 in) was observed with all mass loadings. The amount of the material aerosolized and transported on the bench surrounding the weigh paper was dependent upon the mass of material being poured. These results highlight that weighing activities encountered in forensic labs may be a primary contributor to drug background and may be a potential source of inhalation exposure for chemists.Models of drug addiction in rodents are instrumental in understanding the underlying neurobiology. Intravenous self-administration of drugs in mice is currently the most commonly used model; however, several challenges exist due to complications related to catheter patency. To take full advantage of the genetic tools available to study opioid addiction in mice, we developed a non-invasive mouse model of opioid self-administration using vaporized fentanyl. This model can be used to study various aspects of opioid addiction including self-administration, escalation of drug intake, extinction, reinstatement, and drug seeking despite adversity. Further, this model bypasses the limitations of intravenous self-administration and allows the investigation of drug taking over extended periods of time and in conjunction with cutting-edge techniques such as calcium imaging and in vivo electrophysiology.Proximity-based protein labeling has been developed to identify protein-nucleic acid interactions. We have reported a novel method termed CRUIS (CRISPR-based RNA-United Interacting System), which captures RNA-protein interactions in living cells by combining the RNA-binding capacity of CRISPR/Cas13 and the proximity-tagging activity of PUP-IT. Enzymatically deactivated Cas13a (dCas13a) is fused to the proximity labeling enzyme PafA. In the presence of a guide RNA, dCas13a binds specific target RNA region, while the fused PafA mediates the labeling of biotin-tagged Pup on proximal proteins. The labeled proteins can be enriched by streptavidin pull-down and identified by mass spectrometry. Here we describe the general procedure for capturing RNA-protein interactions using this method.The intracellular interferon regulatory factor 5 (IRF5) dimerization assay is a technique designed to measure molecular interaction(s) with endogenous IRF5. Here, we present two methods that detect endogenous IRF5 homodimerization and interaction of endogenous IR5 with cell penetrating peptide (CPP) inhibitors. Briefly, to detect endogenous IRF5 dimers, THP-1 cells are incubated in the presence or absence of the IRF5-targeted CPP (IRF5-CPP) inhibitor for 30 min then the cells are stimulated with R848 for 1 h. Cell lysates are separated by native-polyacrylamide gel electrophoresis (PAGE) and IRF5 dimers are detected by immunoblotting with IRF5 antibodies. https://www.selleckchem.com/products/rgd-peptide-grgdnp-.html To detect endogenous interactions between IRF5 and FITC-labeled IRF5-CPP, an in-cell fluorescence resonance energy transfer (FRET) assay is used. In this assay, THP-1 cells are left untreated or treated with FITC-IRF5-CPP conjugated inhibitors for 1 h. Next, cells are fixed, permeabilized, and stained with anti-IRF5 and TRITC-conjugated secondary antibodies. Transfer of fluorescence can be measured and calculated as FRET units. These methods provide rapid and accurate assays to detect IRF5 molecular interactions.CD8+CD28- T suppressor cells (Ts) have been documented to promote immune tolerance by suppressing effector T cell responses to alloantigens following transplantation. The suppressive function of T cells has been defined as the inhibitory effect of Ts on the proliferation rate of effector T cells. 3H-thymidine is a classical immunological technique for assaying T cell proliferation but this approach has drawbacks such as the inconvenience of working with radioactive materials. Labeling T cells with CFSE allows relatively easy tracking of generations of proliferated cells. In this report, we utilized antigen presenting cells (APCs) and T cells matched for human leukocyte antigen (HLA) class I or class II to study CD8+CD28- T cell suppression generated in vitro by this novel approach of combining allogeneic APCs and γc cytokines. The expanded CD8+CD28- T cells were isolated (purity 95%) and evaluated for their suppressive capacity in mixed lymphocyte reactions using CD4+ T cells as responders. Here, we present our adapted protocol for assaying the Ts allospecific suppression of CFSE-labeled responder T cells.Cell-free synthesis is a powerful technique that uses the transcriptional and translational machinery extracted from cells to create proteins without the constraints of living cells. Here, we report a cell-free protein production protocol using Escherichia coli lysate (Figure 1) to successfully express a class of proteins (known as hydrophobins) with multiple intramolecular disulphide bonds which are typically difficult to express in a soluble and folded state in the reducing environments found inside a cell. In some cases, the inclusion of a recombinant disulphide isomerase DsbC further enhances the expression levels of correctly folded hydrophobins. Using this protocol, we can achieve milligram levels of protein expression per ml of reaction. While our target proteins are the fungal hydrophobins, it is likely that this protocol with some minor variations can be used to express other proteins with multiple intramolecular disulphide bonds in a natively folded state. Graphic abstract Figure 1.Workflow for cell-free protein expression and single-step purification using affinity chromatography.